Goclothod Dog Training Whistle Professional Doggie Ultrasonic Whistle Stainless Steel Calling Whistle to Stop Barking (Silver)

I'm not sure what I expected but I have tried it on a number of neighborhood dogs and no response from any of them no matter how I adjusted it.

It is not silent like a "professional" whistle should be and as stated.

Nice and easy to use. Good quality with adjustable pitch.

This item had no operation information. It whistles, audible to me, but no response at all from the dogs.